Automatic roof ventilation system

ABSTRACT

A roof ventilation system operable based on environmental parameters is disclosed. The system includes a vent, a fan, a solar panel, a battery and a controller. The vent is positioned within a field of a roof, and includes a first opening configured to allow airflow between regions above and below the roof. The fan is positioned to generate an air flow through the vent. The solar panel is positioned on the roof in a location such that the solar panel receives solar radiation. The battery is electrically connected to the solar panel. The controller is in communication with the fan, and is configured to drive the fan based on at least one environmental parameter.

CLAIM FOR PRIORITY

This application claims the priority benefit under 35 U.S.C. §119(e) of Provisional Application Ser. No. 60/793,337, filed Apr. 18, 2006. The full disclosure of this priority application is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This application relates generally to building ventilation and specifically to roof ventilation.

2. Description of the Related Art

Energy efficiency is a serious consideration in new home design. New homes require ways to minimize energy requirements to maintain comfortable living spaces. One of the most common energy losses in a home is due to heat transfer through the attic. In warm climates, heat builds up in the attic from solar energy incident on the roof. In colder climates, moisture builds up in the attic, robbing the insulation of much of its R value. Early efforts at minimizing the effects of heat and/or moisture build-up focused on insulation between the living space and the attic. Gable vents and dormer type passive ventilation systems have been incorporated to ventilate the attic. U.S. Pat. No. 6,050,039 to O'Hagin describes one such camouflaged passive ventilation system. However, this passive ventilation system does not teach a camouflaged active ventilation system.

In other systems, active grid-powered ventilation systems using gable vents and powered dormer type vents have been used to increase the ventilation of the attic. These grid-powered active ventilation systems require increased operation and installation costs compared with passive systems. In the southwest, many homes have low pitch, hip roofs which have no gables, and dormers may destroy the aesthetics of a design if improperly located or too numerous. Therefore, these systems have proven to be inadequate.

What is needed is an improved ventilation system that will minimally detrimentally affect the appearance of a building design if used in adequate numbers to properly ventilate the attic, and is applicable to many roof configurations and with many types of roofing materials, while offering low operation and installation costs relative to other active ventilation systems. In addition, there is a need to provide a ventilation system automatically operable based on varying environmental conditions with minimal energy consumption.

SUMMARY OF THE INVENTION

Preferred embodiments of the present invention provide a roof ventilation system which is operable based on varying environmental conditions with minimal energy consumption. In accordance with a preferred embodiment, a roof ventilation system is provided for a sloped roof having a ridge and an eave. The system comprises a first plurality of vents arranged generally linearly and positioned within the roof proximate one of the ridge and the eave. Each of the vents comprises a vent member comprising an opening that permits airflow between regions above and below the roof; and a fan configured to generate an air flow through the opening. In addition, the ventilation system includes a controller in communication with the fans of the vents. The controller is configured to drive the fans based on at least one environmental parameter.

In accordance with another preferred embodiment, a roof ventilation system is provided for a sloped roof having a ridge and an eave. The system comprises a first plurality of vents arranged generally linearly and positioned within the roof proximate the ridge. Each of the first plurality of vents comprises: a vent member comprising an opening that permits airflow between regions above and below the roof, and a fan configured to generate an air flow through the opening. The system also comprises a second plurality of vents arranged generally linearly and positioned within the roof proximate the eave. The second plurality of vents permit airflow between the regions above and below the roof. The second plurality of vents include no fans. The system further comprises a controller in communication with the fans of the first plurality of vents. The controller is configured to drive the fans based on at least one environmental parameter.

In accordance with another preferred embodiment, a roof ventilation system is provided comprising a vent configured to be positioned within a field of a roof. The vent includes a first opening configured to allow airflow between regions above and below the roof. In addition, the ventilation system includes a fan configured to be positioned to generate an air flow through the vent, and a solar panel configured to be positioned on the roof in a location such that the solar panel receives solar radiation. The ventilation system also includes a battery configured to be electrically connected to the solar panel so that the solar panel charges the battery from solar radiation. The system is operated by a controller adapted to communicate with the fan. The controller is configured to drive the fan based on at least one environmental parameter.

In accordance with yet another preferred embodiment, a roof having a ventilation system is provided comprising: a roof comprising a layer of roof cover elements; and a vent configured to be positioned within the layer of roof cover elements. The vent includes a first opening configured to allow airflow between regions above and below the roof. The vent mimics an appearance of one or more of the roof cover elements. The system also comprises a fan configured to be positioned to generate an air flow through the vent; a solar panel configured to be positioned on the roof in a location such that the solar panel receives solar radiation; a battery configured to be electrically connected to the solar panel so that the solar panel charges the battery from solar radiation; and a controller adapted to communicate with the fan. The controller is configured to drive the fan based on at least one environmental parameter. The controller is configured to be powered by the battery.

For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described above and as further described below. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.

All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments having reference to the attached figure, the invention not being limited to any particular preferred embodiment(s) disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a vent positioned in a roof in accordance with one embodiment of the present invention;

FIG. 2 is a schematic perspective view of one embodiment of a roof ventilation system;

FIG. 3A is a schematic perspective view of another embodiment of a roof ventilation system;

FIG. 3B is a schematic cross-sectional view of the roof ventilation system of FIG. 3A;

FIG. 4 is a schematic cross-sectional view of a roof ventilation system which shows sensor locations;

FIG. 5 is a perspective view of another embodiment of a roof ventilation system having a plurality of vents;

FIG. 6 is a schematic diagram of the roof ventilation system of FIG. 5.

FIG. 7 is a flowchart illustrating an exemplary operation of a roof ventilation system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a building 1 with a roof 2 comprising two fields 3 a and 3 b that are joined at their upper ends to define a ridge 4. Lower edges 5 of the fields are referred to as an “eave.” The fields 3 a and 3 b typically comprise a roof deck covered with roof cover elements such as tiles (e.g., clay or concrete), shingles (e.g., wooden, clay, or composition), or sheeting (e.g., metal). The illustrated roof is suitable for having one or more vents 10 according to one embodiment of the invention. Also, skilled artisans will appreciate that the vents may be provided in a wide variety of different types of roofs, including those not having ridges or sloped fields. In FIG. 1, the vent 10 is positioned on the central part of the field 3 a. In other embodiments, the vent may be positioned on a different part of the field, depending on the ventilation needs.

FIG. 2 illustrates one embodiment of a roof ventilation system 20. The illustrated ventilation system 20 is positioned within a field of a tile roof. The illustrated ventilation system 20 includes a first vent member 21, a second vent member 22, a fan 23, a solar panel 24, a battery 25, a controller 26, one or more sensors 27, and a user interface 28. It will be appreciated that a plurality of ventilation systems 20 can be provided in one roof. Skilled artisans will also appreciate that a plurality of ventilation systems 20 can share a common battery 25, controller 26, sensors 27, and/or user interface 28.

The first vent member 21 is configured to be positioned at an opening in the roof. The first vent member 21 includes a vent opening 29 penetrating the first member 21. The vent opening 29 is configured to allow airflow between regions above and below the roof. The regions below the roof may include an attic or a living space of a building. The vent opening 29 is covered by a screen to prevent entry of insects, vermin, and debris larger than the screen openings.

The second vent member 22 is configured to reside above the first vent member 21, serving as a cap for the first vent member 21. The second vent member 22 also includes a vent opening (not shown) which is in fluid or ventilating communication with the vent opening 29 of the first vent member 21. This configuration allows airflow while preventing water or rain from entering the regions below the roof. Further details of the first and second vent members are disclosed in U.S. Pat. No. 6,050,039, the disclosure of which is incorporated herein by reference. In the illustrated embodiment, the second vent member 22 mimics an appearance of one or more of the roof cover elements (e.g., tiles, shingles, or sheeting).

The fan 23 is configured to generate airflow through the vent openings of the vent members 21 and 22. In the illustrated embodiment, the fan 23 is positioned in a region (for example, the attic) below the roof adjacent the vent opening 29 of the first vent member 21. The fan 23 is in line with the vent opening 29 to efficiently generate airflow through the vent opening 29. Preferably, the fan 23 includes a fan blade driven by a motor, both contained within a fan housing which is attached to the underside of the first vent member 21 by a fan adaptor (not shown). A skilled artisan will appreciate that the position and configuration of the fan 23 may be varied depending on the design of the ventilation system. For example, it may be possible to mount the fan 23 and its associated motor between the first and second vent members 21, 22.

The controller 26 is configured to drive the motor of the fan 23. The controller 26 is electrically connected to the fan 23. As will be later described, the controller 26 is configured to drive the fan 23 based on at least one environmental parameter. The controller preferably includes a CPU or microprocessor, a memory device, and other peripheral components so as to collect, process, store, and transmit electronic data.

The battery 25 is configured to supply power to the controller 26. The battery 25 is electrically connected to the controller 26. The battery 25 preferably serves as a main power source for the controller 26. In certain embodiments, an additional or auxiliary power source (not shown) may be provided to the controller 26. An exemplary additional power source is a domestic AC power source (e.g., from a municipal power grid). The domestic power source may be directly connected to the controller 26. In other embodiments, the domestic power source may be connected to the battery 25 to charge the battery 25 in case the solar panel 24 is not functional.

The solar panel 24 is configured to convert solar energy into electricity, and to supply the electricity to the battery 25 for storage. In the illustrated embodiment, the solar panel 24 is electrically connected to the battery. In certain embodiments, the solar panel 24 may be indirectly connected to the battery via the controller 26. The solar panel 24 is configured to be positioned on the roof in a location such that the solar panel receives solar radiation. The illustrated solar panel 24 is mounted on the second vent member 22. In other embodiments, the solar panel may be positioned at any suitable site on the roof. Preferably, the site is where the solar panel can effectively collect solar radiation. It will be appreciated that more than one solar panel can be associated with each ventilation system 20.

The one or more sensors 27 are configured to collect various environmental parameters on which the controller operation is based. Examples of environmental parameters include, but are not limited to, temperature, humidity, toxicity, moisture, precipitation, airflow, and ambient light level. The sensors 27 are configured to measure environmental parameters and convert the parameters into electronic data. Each of the sensors has means for measuring a respective environmental parameter. In addition, each of the sensors may further include a microprocessor, a memory, and peripheral components to collect, process, store, and transmit data to the controller 26.

Examples of the sensors include, but are not limited to, a temperature sensor, a humidity sensor, an air flow sensor, and a toxicity sensor. In certain embodiments, two or more of the sensors may be combined to provide measurements of multiple environmental parameters. The sensors 27 are all electrically connected to or adapted to communicate with the controller 26. The sensors may be powered by the battery via the controller or by another power source. The sensor positions will be later described with reference to FIG. 4.

The user interface 28 is configured to displays measurements of the at least one environmental parameter collected from the sensors 27. The user interface 28 may also be configured to allow a user to control the fan via the controller 26. The user interface 28 includes a display device such as an LCD or CRT screen. Optionally, the user interface 28 may include an input device such as a touch pad screen and/or push buttons. In certain embodiments, the input device may be a key board or key pad. The user interface 28 is electrically connected to or adapted to communicate with the controller 26. In certain embodiments, the user interface 28 and the controller 26 may be integrated into one device.

FIGS. 3A and 3B illustrate another embodiment of a ventilation system 30. The illustrated ventilation system 30 is positioned within a field of a roof covered by so-called composition shingles or roofing material 301. As shown in FIG. 3B, the roof has a roof deck 302 which may include a sheathing 302 a and an underlay material 302 b overlying the sheathing 302 a. Typically, the sheathing 302 a is formed of plywood, and the underlay material 302 b is formed of tar. The composition shingles 301 are mounted on the underlay material 302 b, as shown in FIG. 3B. The ventilation system 30 includes a vent member 31, a fan 33, a solar panel 34, a battery 35, a controller 36, one or more sensors 37, and a user interface 38. It will be appreciated that a plurality of ventilation systems 30 can be provided in one roof. Skilled artisans will also appreciate that a plurality of ventilation systems 30 can share a common battery 35, controller 36, sensors 37, and/or user interface 38.

The vent member 31 is configured to reside over an opening 303 in the roof deck 302. The vent member 31 includes an upper member 31 a and a lower member 31 b. The lower member 31 b is mounted on the roof deck 302 (either on the sheathing 302 a or on the underlay material 302 b). The illustrated upper member 31 a is configured to slightly protrude above the level of the top surfaces of the shingles 301. In addition, the upper member 31 a has a flange 31 c at its lower edge. The flange 31 c may be configured to allow airflow underneath it to the opening 303 while preventing ingress of rain or snow. The vent member 31 includes one or more vent openings 39. The vent openings 39 are configured to allow airflow between regions above and below the roof. The illustrated vent openings 39 comprise louvers. A louver includes a number of narrow slits formed in parallel to each other. The slits, however, are not directly over the opening 303 in the roof. Yet, the vent openings 39 are configured to be in fluid or ventilating communication with the opening 303 of the roof by having space between the vent member 31 and the roof deck 302. This configuration allows ventilation while preventing water or rain from entering the regions below the roof. The vent member 31 also includes a solar panel 34 mounted on its upper surface.

Configurations and interconnections of the fan 33, the solar panel 34, the battery 35, the controller 36, the one or more sensors 37, and the user interface 38 are as described above with respect to FIG. 2.

Other types or configurations of roof vents may be suitable for being adapted to the ventilation systems of the present invention. Examples of such roof vents without limitation are shown and disclosed in U.S. Pat. Nos. 6,050,039; 6,129,628; 6,447,390; and 6,491,579; and U.S. Design patent application Ser. No. 29/195,520 filed on Dec. 11, 2003, the full disclosures of which are incorporated herein by reference.

FIG. 4 illustrates the positions of the sensors of FIG. 2 or 3 according to one embodiment. In the illustrated embodiment, a temperature sensor 401 is positioned in a living space 7. In addition, a humidity sensor 402 and a toxicity sensor 404 are also positioned in the living space 7 at a suitable level and location. An airflow sensor 403 is positioned in an attic 6 to monitor airflow near a roof vent 41. In other embodiments, the sensors may be positioned at different locations. In addition, two or more sensors of the same type may be provided at several different locations. Any of a wide variety of different combinations and types of sensors can be provided.

FIG. 5 illustrates another embodiment of a ventilation system including a plurality of vents. The illustrated ventilation system is suitable for a sloped roof 2 having a ridge 4 and an eave 5. In certain embodiments, the ventilation system may be modified for various other types of roofs. The ventilation system includes a first plurality of vents 50 a-50 d arranged generally linearly. The first plurality of vents 50 a-50 d are positioned within the roof 2 proximate the ridge 4. The ventilation system also includes a second plurality of vents 50 e-50 h arranged generally linearly and positioned within the roof 2 proximate the eave 5. The second plurality of vents 50 e-50 h are arranged generally along a line that is generally parallel to a line along which the first plurality of vents 50 a-50 d are generally arranged.

Each of the first plurality of vents 50 a-50 d includes a vent member having an opening that permits airflow between regions above and below the roof. Each of the vents 50 a-50 d also includes a fan configured to generate airflow through the opening, and a solar panel positioned to receive solar radiation. The configurations of the vents 50 a-50 d may be as described above with respect to FIG. 2 or 3, but other configurations are also possible.

Each of the second plurality of vents 50 e-50 h is configured to permit airflow between the regions above and below the roof. Optionally, the second plurality of vents 50 e-50 h may have the same configuration as that of the first plurality of vents 50 a-50 d either with or without fans.

The ventilation system is configured to generate airflow to enter the second plurality of vents 50 e-50 h and to exit the first plurality of vents 50 a-50 d, as denoted by an arrow in FIG. 5. This configuration can be achieved by generating outward airflow using the fans of the first plurality of vents 50 a-50 d. In a preferred embodiment, the vents 50 e-50 h do not include fans. In an alternative embodiment, the airflow may be enhanced by generating inward airflow with fans associated with the second plurality of vents 50 e-50 h. In this alternative, the fans of the second plurality of vents 50 e-50 h preferably either spin in an opposite direction to the fans 50 a-50 d or have an inverse curvature of the fan blades.

FIG. 6 illustrates a schematic diagram of the ventilation system of FIG. 5. The ventilation system includes the plurality of first vents 50 a-50 d, the plurality of second vents 50 e-50 h (not shown), a plurality of fans 53 a-53 d, a plurality of solar panels 54 a-54 b, a battery 55, a controller 56, one or more of sensors 57, and a user interface 58.

Each of the first vents 50 a-50 d is provided with a fan and a solar panel. The solar panels may be mounted on the vents or the cover members of the vents as described with respect to FIG. 2 or 3. Although not shown, each of the second plurality of vents 50 e-50 h may be provided with a fan and/or a solar panel.

The battery 55 is configured to supply power to the controller, and is electrically connected to the solar panels of the vents 50 a-50 d. The illustrated system includes only one battery. In certain embodiments, however, the system may have back-up batteries.

The controller 56 is configured to be in electrical communication with the fans 53 a-53 d of the vents 50 a-50 d. The controller 56 is configured to drive the fans based on at least one environmental parameter as described above with respect to FIG. 2. Examples of environmental parameters include, but are not limited to, temperature, humidity, precipitation, toxicity, moisture, air flow, and ambient light level. The controller 56 is configured to collect environmental parameter data from the sensors 57, and drive the fans 53 a-53 d based on the data.

In one embodiment, the controller 56 is configured to operate on a software program for providing optimal ventilation. The program first determines whether the environmental parameters are within predetermined ranges. If not, the program instructs the controller 56 to drive the fans 53 a-53 d. In certain embodiments, the program may turn on some of the fans while turning off the others. In other embodiments, the program may control the speed of each fan. The configurations of the sensors 57 and the user interface 58 are as described above with respect to FIGS. 2 and 4.

FIG. 7 is a flowchart illustrating an exemplary operation of any one of the roof ventilation systems of the embodiments described above. It should be understood that FIG. 7 illustrates one embodiment of a control system, and that many alternative embodiments are possible. The system can operate on a prioritized determination scheme based on two or more environmental parameters. In the illustrated example, the system operates based on measurements of toxicity, temperature, and humidity. In other examples, other environmental parameters can be used (either in place of or in addition to those of FIG. 7) for the ventilation control. Alternatively, a subset of the parameters shown in FIG. 7, possibly in addition to one or more other parameters not shown in FIG. 7, can be used for the ventilation control. In the flowchart, some blocks can be omitted. In addition, two or more blocks can be combined with one another.

In block 71, the controller of the system receives toxicity data from a toxicity sensor positioned preferably in a living space. The controller determines whether the airborne concentration of a toxic gas is above a predetermined level A1. An exemplary toxic gas is carbon monoxide (CO). The predetermined level for carbon monoxide (CO) can be set to, for example, 35 PPM, the limit allowed by the U.S. Occupational Safety and Health Administration (OSHA). In one embodiment, the system does not allow a user to adjust the predetermined level. In another embodiment, the system allows the adjustment of the predetermined level. If the airborne concentration of the toxic gas is above the predetermined level A1, the controller turns on a fan at block 74. In an embodiment in which the system includes a plurality of fans, the controller can turn on two or more fans for effective removal of the toxic gas.

If the airborne concentration is below the predetermined level A1, the controller preferably determines whether the current temperature of the attic or living space is above a predetermined temperature T1 (block 72). If yes, the controller preferably turns on the fan(s). If no, the controller preferably determines whether the current humidity exceeds a predetermined humidity level H1 (block 73). For example, the predetermined humidity level can be 35% RH. The predetermined toxicity level A1, temperature T1, and humidity level H1 can be adjusted using a user interface. In other embodiments in which other parameters are used for the ventilation control, the predetermined levels of the other parameters can also be adjusted using a user interface. If the current humidity exceeds the predetermined humidity level H1, the controller turns on the fan(s). If not, the process goes to block 75, in which the controller waits a predetermined period of time before restarting the entire process. Similarly, the controller can, in one embodiment, only turn on the fan(s) for a predetermined period of time at block 74, and wait at block 75 before restarting the process. The block 75 can be omitted in certain embodiments. It will be understood that the control of the fans may be based on the outcome of various different logical and/or mathematical formulae involving the sensed environmental parameters. FIG. 7 is just one example of such.

This configuration allows the system to save power while achieving optimal condition for an attic and/or living space. The controller can also control the speed of the fan(s) depending on needs. These configurations are particularly useful when the system is powered only by solar energy and not by a municipal power grid. A skilled artisan will appreciate that various other algorithms can be provided for suitable ventilation.

In certain embodiments, any of the roof ventilation systems described above can be combined with a central air conditioning system of a house or building. The roof ventilation system can enhance the efficiency of air conditioning by removing heat build-up from an attic space. In the embodiments described above, the roof ventilation system can be powered by solar energy, and thus can effectively reduce overall energy consumption in climate control of a house or building. The roof ventilation system also helps to more efficiently comply with regulations on indoor air quality such as ASHRAE (The American Society of Heating, Refrigerating and Air-Conditioning Engineers) Standard 62-1989 (or similar later provisions), OSHA proposed regulations on indoor air quality, and OSHA general regulation (29 CFR 1910).

Although this invention has been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications thereof. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above, but should be determined only by a fair reading of the claims that follow. 

1. A roof ventilation system for a sloped roof having a ridge and an eave, the system comprising: a first plurality of vents arranged generally linearly and positioned within the roof proximate one of the ridge and the eave, each of the vents comprising: a vent member comprising an opening that permits airflow between regions above and below the roof, and a fan configured to generate an air flow through the opening; and a controller in communication with the fans of the vents, the controller being configured to drive the fans based on at least one environmental parameter.
 2. The system of claim 1, wherein the first plurality of vents are positioned proximate to the ridge.
 3. The system of claim 1, wherein each of the vents further comprises a solar panel positioned to receive solar radiation.
 4. The system of claim 3, further comprising a battery electrically connected to the solar panels of the vents.
 5. The system of claim 4, wherein the battery is configured to provide electrical power to the fans of the vents and/or the controller.
 6. The system of claim 1, further comprising a second plurality of vents arranged generally linearly and positioned within the roof proximate the other of the ridge and the eave, the second plurality of vents permitting airflow between the regions above and below the roof.
 7. The system of claim 6, wherein each vent of the second plurality of vents comprises: a vent member comprising an opening that permits airflow between the regions above and below the roof; a fan configured to be driven by the controller and to generate an airflow through the opening; and a solar panel electrically connected to the battery and positioned to receive solar radiation.
 8. The system of claim 1, wherein each of the vents further comprises a cover member configured to cover the vent member, the cover member including an opening in fluid communication with the opening of the vent member.
 9. The system of claim 8, wherein each of the vents further comprises a solar panel positioned to receive solar radiation, and wherein the solar panel of each of the vents is mounted on the cover member of the vent.
 10. The system of claim 1, wherein the environmental parameter comprises one or more selected from the group consisting of temperature, humidity, toxicity, moisture, air flow, and ambient light level.
 11. A roof ventilation system for a sloped roof having a ridge and an eave, the system comprising: a first plurality of vents arranged generally linearly and positioned within the roof proximate the ridge, each of the first plurality of vents comprising: a vent member comprising an opening that permits airflow between regions above and below the roof, and a fan configured to generate an air flow through the opening; a second plurality of vents arranged generally linearly and positioned within the roof proximate the eave, the second plurality of vents permitting airflow between the regions above and below the roof, the second plurality of vents including no fans; and a controller in communication with the fans of the first plurality of vents, the controller being configured to drive the fans based on at least one environmental parameter.
 12. The system of claim 11, wherein each of the first plurality of vents further comprises a solar panel positioned to receive solar radiation.
 13. The system of claim 12, further comprising a battery electrically connected to the solar panels of the first plurality of vents.
 14. A roof ventilation system comprising: a vent configured to be positioned within a field of a roof, the vent including a first opening configured to allow airflow between regions above and below the roof; a fan configured to be positioned to generate an air flow through the vent; a solar panel configured to be positioned on the vent such that the solar panel receives solar radiation; a battery configured to be electrically connected to the solar panel so that the solar panel charges the battery from solar radiation; and a controller adapted to communicate with the fan, the controller being configured to drive the fan based on at least one environmental parameter, wherein the battery is configured to provide electrical power to the fan and/or the controller.
 15. The system of claim 14, wherein the controller is configured to control the speed of the fan.
 16. The system of claim 14, wherein the controller comprises a microprocessor.
 17. The system of claim 14, wherein the vent comprises a first vent member configured to be positioned at an opening in the roof, and a second vent member configured to reside above the first vent member, the second vent member comprising a second opening, the second opening being in fluid communication with the first opening.
 18. The system of claim 17, wherein the solar panel is mounted on the second vent member.
 19. The system of claim 14, wherein the environmental parameter comprises one or more selected from the group consisting of temperature, humidity, toxicity, moisture, air flow, and ambient light level.
 20. The system of claim 14, wherein the environmental parameter comprises two or more environmental parameters, and wherein the controller is configured to control the fan based on a logical and/or mathematical formula involving measurements of the parameters.
 21. The system of claim 14, further comprising a temperature sensor adapted to communicate with the controller.
 22. The system of claim 14, further comprising a humidity sensor adapted to communicate with the controller.
 23. The system of claim 14, further comprising an air flow sensor adapted to communicate with the controller.
 24. The system of claim 14, further comprising a toxicity sensor adapted to communicate with the controller.
 25. The system of claim 14, wherein the controller includes a user interface that displays measurements of the at least one environmental parameter.
 26. The system of claim 25, wherein the user interface is configured to allow a user to control the fan.
 27. A roof having a ventilation system comprising: a roof comprising a layer of roof cover elements; a vent configured to be positioned within the layer of roof cover elements, the vent including a first opening configured to allow airflow between regions above and below the roof, the vent mimicking an appearance of one or more of the roof cover elements; a fan configured to be positioned to generate an air flow through the vent; a solar panel configured to be positioned on the roof in a location such that the solar panel receives solar radiation; a battery configured to be electrically connected to the solar panel so that the solar panel charges the battery from solar radiation; and a controller adapted to communicate with the fan, the controller being configured to drive the fan based on at least one environmental parameter, the controller being configured to be powered by the battery.
 28. The system of claim 27, wherein the solar panel is mounted on the vent.
 29. The system of claim 27, wherein the environmental parameter comprises one or more selected from the group consisting of temperature, humidity, toxicity, moisture, air flow, and ambient light level.
 30. The system of claim 27, wherein the controller includes a user interface that displays measurements of the at least one environmental parameter.
 31. The system of claim 30, wherein the user interface is configured to allow a user to control the fan. 